1. Field of the Invention
The present invention relates generally to systems, methods and devices for determining geographic information, and specifically to distributed systems, methods and devices for interpreting spatial and geographic data and presenting said data to a user.
2. History of the Related Art
Recent years have seen a proliferation in the field of navigation and way-finding, particularly as applied to automotive travel. Many new vehicles are equipped with navigation devices for aiding the operator in his or her travels. Although these developments are a welcome improvement over maps, they still suffer from limitations imposed by the very nature of automotive travel. For example, routes for car navigation are confined to street networks and any instruction given to navigators is always with reference to the underlying network. The ride from Boston to New York, for instance, takes place on the different types of street networks. Automotive networks include a number of physical constraints on the movement of vehicles, such as one-way streets, on-ramps, exit ramps, and the like. Moreover, automotive networks contain a number of rules, such as traffic lights, speed limits and other traffic laws. These rules and constraints, together with the street network provide a forgiving system with regard to user and data inaccuracies. As long as route instructions are not given too late, user location and data inaccuracies do not deter drivers from their chosen route.
Pedestrian navigation, however, is not confined to a network of streets, but includes all passable areas, such as walkways, squares, and open areas, within or outside buildings. A pedestrian decision point is not specific to a junction between two or more streets, but rather it is a function of the actual position of the pedestrian. This systemic feature of pedestrian navigation results from the natural freedom associated with walking. Pedestrians are free to choose their own path, get on and off street networks anywhere and anytime, take shortcuts, or cross squares. Similar navigation problems are associated with aircraft and vessels, which can more freely choose and select their route without the confines of a street or highway network.
Because of these difficulties associated with pedestrian navigation, many pedestrians, pilots and ship navigators still rely on maps as a route-finding tool. Maps an adequate means for understanding spatial environments, as well as for performing tasks such as way finding, trip-planning, and location-tracking. However, static traditional maps have several disadvantages. First, maps necessarily have a fixed orientation. That is, the map always faces in one direction (typically north). A user, however, may be facing any direction at any given moment. Hence, in order to understand the map, a user needs to perform some kind of rotation, either of himself or of the map to align his frame of reference with the map's frame of reference. This process puts an immense cognitive load on the users, because it is not always intuitive and may present considerable difficulties, especially in cases of complex, uniform or unfamiliar spatial environments.
Maps are also hindered by the fact that they have a fixed scale that cannot be changed to a different granularity level. This limitation is one of the most restrictive aspects of paper maps. The scale determines the level of zooming into a spatial environment, as well as the level of detail and the type of information that is displayed on a map. Users, however, need to constantly change between different scales, depending on whether they want a detailed view of their immediate surrounding environment or a more extensive and abstract view in order to plan a trip or find a destination. Current solutions to the problem include tourist guides that comprise maps of a specific area at many different scales. Tourist guides, however, are bulky books, difficult to carry around, and search time is considerable as they typically consist of hundreds of pages.
Maps also fail to accommodate rapid changes in our natural and urban environments. On a map, all spatial environments and the objects that they encompass, whether artificial or natural, are displayed statically although they are actually dynamic and change over time. Artificial spatial objects, such as buildings, may get created, destroyed, or extended, while others, such as land parcels, may merge, shrink, or change character (e.g., when a rural area is developed). The same holds true for natural features, for instance, a river may expand or shrink because of a flood. The static 2-dimensional map is restricted to representing a snapshot in time and the information on it may soon become obsolete, or worse, misleading.
Attempts at electronic maps or geographic information systems have also proven unworkable for practical reasons. One deficiency found in current geographic information systems is that the systems are purely quantitative. That is, any feedback provided to the user is typically in a quantitative measurement of distance, such as for example, instructing a user to turn right in fifty meters. While some users may have an intuitive understanding of space and measurement, other users are likely to become more confused and frustrated as they attempt to determine the relationship between the real space in front of them and the quantitative measure of it provided by the geographic information system. As such, the state of the art lacks an integrated geographic information system that can provide information to a user in a manner that is easily accessible, intuitively understood and qualitative in nature.